(3 points) Solve the BVP for the wave equation
$\frac{\partial^2 u}{\partial t^2}(x, t) = \frac{\partial^2 u}{\partial x^2}(x, t)$, $0 < x < \pi$, $t > 0$
$u(0, t) = 0$, $u(\pi, t) = 0$, $t > 0$,
$u(x, 0) = \sin(x) \cos(x)$, $u_t(x, 0) = \sin(x)$, $0 < x < \pi$.
$u(x, t) = $
